The team of seven rafts leaves the first section below Tuotuohoyen and heads for what we called The River at the Top of the World. A large tributary has joined the main Yangtze near here. There was some discussion after the trip whether or not it was longer than the river we began on, but the evidence presented by the Chinese government still points to the source we began on. Only the author of a poorly researched article in Outside Magazine ever treated the tributary as a serious contender.